Is it on a chunk boundary? Are you using any covers? Are they all placed right? Pics might be helpful.
Ok here's the base of the machine:
That is mid-movement so you can see that the line of breakers at the back is about to move on and leave the stone behind, and that the ducts connecting them to the ender chest is currently disconnected whilst the machine is in mid-inchworm. The impulse ducts at the top continue up another 18 blocks. Here's a side view:
And here it is in the middle of clearing out the layer in front of it, it's breaking blocks somewhat randomly once per second:
I suspect that maybe the ducts are a bottleneck. I'm thinking of replacing them all with warp item ducts, but that's a lot of removing and replacing of ducts and covers!
*Edit* Mmm, no. Eventually, all but one of the blocks underneath the smashers broke, the nearest one will not break.
I just tried attaching a retriever to the ender chest end of the warp ducts, and the game crashed. Maybe that will un-block the smasher when I re-load...
*Edit* Nope, retrieval nodes don't make any difference, and replacing everything with warp ducts doesn't work either. My conclusion is: Thermal Expansion and Thermal Dynamics Frame Bores are simply not reliable. Shame, I know AE2 works, but everyone's doing that these days. Any suggestions what else I can do with these 182 terrain smashers? I guess I'll keep hold of them until I find an Uncrafting Table.